1. Field of the Invention
The present disclosure relates to a method of manufacturing light emitting devices.
2. Description of the Related Art
Japanese Laid-Open Patent Publication 2013-042119 discloses preparation of a wafer having a sapphire substrate with semiconductor layers disposed on the upper surface, and subsequent formation of material modified regions (where material properties of the substrate crystal are altered, hereinafter referred to as “modified region(s)”) by laser beam irradiation inside the sapphire substrate. Further, by cleaving the wafer along scribe lines coincident (as viewed from above the wafer) with the modified regions, a plurality of light emitting devices can be obtained from a single wafer (so-called die separation, singulation, or dicing).
Since each light emitting device obtained by die separation according to the light emitting device method of manufacture referenced above has a rectangular shape in plan view, wafer cleaving lines establish a rectangular grid pattern in plan view. Consequently, even if cracks extend along cleaving lines coincident with the modified regions, the probability is low that those cracks extend into regions corresponding to the light emitting devices after die separation (subsequently referred to as light emitting device regions). However, in the case of light emitting devices having a hexagonal shape in plan view, linear extension of the cleaving lines laterally intrudes into light emitting device regions. Accordingly for hexagonal light emitting devices, there is a higher probability that cracks propagating from the modified regions extend into light emitting device regions. Since cracks that extend into light emitting device area have a detrimental impact on wafer cleaving and result in defects such as die chipping and yield reduction.
One of the objects of the present invention is to provide a light emitting device method of manufacture that can suppress crack extensions from modified regions into light emitting device active regions and can increase yield.